Automatic plotting systems are known and referred to in the art as interactive reproduction systems, wherein an operator may construct or reconstruct an object on a variety of mediums using a computer for processing and storing coordinate position data and for transmitting the data to control the operation of a plotting or cutting instrument.
The automatic reproduction system typically includes a mechanical X-Y plotting device having X and Y servo drive motors which control the position of the plotting or cutting instrument in response to the input of position data in the form of X and Y cartesian coordinates from a computer storage. While X and Y plotting devices are suitable for many plotting operations, the nature and mobility of such devices limits the number of points into which an object may be resolved and such devices cannot provide the high degree of resolution and accuracy required in many plotting operations. Moreover, prior rectangular coordinate plotting systems are typically limited to a particular resolution in that they are adapted to plot only a given number of points within a given unit of measure and this resolution cannot be conveniently varied from plot to plot. The plots from such a system can result in a number of lines oriented at discernible angles rather than appearing as smooth lines. Typically, the X-Y mechanical plotter operates on the principle of rolling friction and has a reduced effectiveness when cutting in a highly resistant medium such as wood, stone, metal, etc.
Accordingly, an important object of the present invention is to provide an improved mechanical plotting apparatus having increased mobility for use in accurately forming an object in an automatic reproduction system.
Another important object of the present invention is to provide a plotting apparatus for use in an automatic plotting system which provides a high degree of resolution and accuracy to the object being formed.
Another important object of the present invention is the provision of a plotting apparatus having a power drive which will operate the plotting or cutting instrument effectively in highly resistent mediums.
Yet another important object of the present invention is the provision of a plotting apparatus which is controlled by the input of angular coordinates and operates on the principle of angular rotational motion to provide an infinite degree of resolution and smooth lines in the plotting operation.